Laserfiche WebLink
<br />6 <br /> <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />ABSTRACTS <br /> <br />Instream Flow <br /> <br />Instream flow recommendations using a meso-habitat approach for native fish <br />populations in the Yampa and Colorado Rivers. <br /> <br />Anderson, Rickl, and Gregory B. Stewart2 <br /> <br />I Colorado Division of Wildlife, Grand Junction. CO 2 Oregon State University, <br />Corvallis. OR <br /> <br />Establishment of instream flows are generally considered to be a valuable tool for <br />maintaining declining or threatened native fish populations. In 1999 the DOW began a <br />research project to make biologically justified instream flow recommendations. <br />Anderson and Stewart (2003) designed a Meso-Habitat approach similar in concept to <br />PHABSIM in that it included a hydraulic model to simulate flow conditions and a species <br />habitat suitability index used to predict habitat availability, Channel topography was <br />surveyed with RTK GPS at six study sites on three rivers. A 2-D flow model was used to <br />simulate depths and velocities for each site. A large part of th\:; study was to develop <br />meso-habitat criteria for two native fish, the flannelmouth and bluehead suckers. This <br />was accomplished by examining the relationship between their abundance within sub- <br />reaches of each study site. The physical attributes of each sub-reach were correlated <br />against fish abundance. The output of the Meso-Habitat methodology was four meso- <br />habitat types for each species that quantified unusable, unsuitable, marginal and optimal <br />habitat availability for a range of tlows. Channel geomorphology was found to be similar <br />for the Yampa River and I5-Mile Reach of Colorado River. Flows that optimized habitat <br />were also similar and in the range of 900 to 1,200 cfs. However because of differences in <br />historic water availability the minimum base now recommendation for the Yampa River <br />was 200 cfs and it was 600 cfs for the I5-Mile Reach. <br /> <br />Gunnison River I Aspinall Unit Temperature Study - Phase II <br /> <br />Cutler, Amyl, and Jean Marie Boyer:! <br /> <br />I Bureau of Reclamation; 2 fl.vdrosphere Consultants <br /> <br />A reservoir temperature model, CE-QUAL-W2. and a river temperature model, QUAL- <br />2K, are used to analyze reservoir operational scenarios to determine the range of release <br />temperatures possible from Crystal Reservoir and temperature-related effects on the <br />Gunnison River downstream for the purpose of enhancing the survivability endangered <br />native fish species, the Colorado pikeminnow, Historic reservoir release temperatures are <br />compared to modeled release temperatures resulting from the proposed "Flow <br />Recommendations", and from two hypothetical selective withdrawal structures at the <br />